The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Recently, research has been undertaken to enhance fuel efficiency of a vehicle, such as by designing a two cylinder engine or a three cylinder engine.
However, enhancing output and fuel efficiency of the two cylinder engine or the three cylinder engine may be limited according to various vehicle driving conditions.
Also, the two cylinder engine or the three cylinder engine outputs relatively serious vibration and applying an element, such as a balance shaft, for suppressing vibration to the two cylinder engine or the three cylinder engine may be limitative.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.